X-ray tube.



E. W. CALDWELL.

XRAY TUBE.

APPLIoATIoN FILED mans, 1909.

Patented June 18, 1912.

` W/TNESSES @from/frs .EUGENE W. CALDWELL, oF NEW Yom; Ni Y.

1yr-RAY TUBE. A

specification of Letters raient.

Patented June 18,- 1912.

Application tiled. March 13; 1909. Serial No. 483,182.

To all whom t may concern:

Be it known. that I, EUGENE W. CALD- wanna citizen of the United States,and residenti of the city, county, and State of New York.,- have made a certain new and useful Invention Relating to X-R'ay Tubes, of which the following is a specification, taken in. connectionv With` the accompanying drawings, yforming part of the same.

This invention relates to X-ray tubes and rela/tesfespecially to tubes adapted for use in radiographic Work andv inl Which the target is formed. with a recess which; the cathode vstream enters toimpinge on the focal surfaceat the bottom of the recess and thereby generate X-rays which may be transmitted through the recess, the inclosing portions of the target acting as a shield to intercept all the rays. except those constituting'the useful cone of Xrays, Which may pass through a Windev` 'in the cathode itself or through.a laterally arranged Window in the target.

In the' accompanying drawing showing illustrative embodiments of this invention in a somewhat diagrammatic Way in which the ,same reference numerall refers to similar parts'in the several gures, Figure 1 isa longitudinal section of an X-ray tube. Fig. 2 isla similar sectional view of a modified form. of tube..

As indicated in the` illustrative embodi vthe Xqfays-andv other undesirable radiation to be readily supported around the tube body Where'the Xrays are developed. The target which as indicated is quite closely embraced by the body H1 of: the tube may comprise the heavy metallic portion 11 secured to the support 12A desired and'provided With the focalisurf-ace 8 of platinum or'other suitable material to receive-the cathode stream. The target may as indicated be formed with a the target being formedI of heavy metal, such as copper, which is substantiall impervious to the X-rays and; other radiation emitted from the focal surface. If desired,

-suitable intercepters or ridges 10 may be formed ontheshield extensions of the target so` as to intercept undesirable radiation and minimize `the secondary radiatioi issuing from the target recess. If desired, a suitableglass envelop 15 may be provided Within the tube inclosin the target to the desired extent so as to mo ify to the desired extent the electrical discharge through1thetube;.

The cathode ma be supportedin the ex.- hausted tube cham er by any desired means as by the stemjfl connected 'to-the cathode adjacent its outer edge and mounted in asuitable arm 3 of the tube and connected with arm.. The cathode may also 1n some cases if desired be further supported in proper posi-j tion with relation to the target by suitable retainers 7 fused into or otherwise supported by the tube. As indicated` the cathode may be formed With acentrally locatedl Window 16 transparent to the Xrays--which-ma be either in the form: of an aperturethnough the cathode or a` comparatively thin plate of aluminum so as to allow the useful cone` of X-rays to be transmitted readily Without interrupting the concave Working face ofthe cathode. When the tube is operated the cathode stream enters the targetrecessand is focused 011 thefocal surface 8V developing X-rays Whichafter transmission through the window 16 of the cathode fiorm the useful pencil of raysl. While of course being useful for treat-ment purposes this ray cone is especially desirablefor radiographic work because it produces sharpshadows by reason of the elimination of the undesirable secondary and irregular radiation. i

In the illustrative embodiment of the in vention shown in Fig; 25 the body 1 of the glass tube is indicated ashavingi a substantially cylindrical form and closely inclosing the cathode and target. The-target is mount'- ed on a suitable tubular or other su port 112 held within the reduced portion 2.o the exliaustedl tube and electrically connected with the target terminal 13. l The target may suitable recess lfl, the shield extensions 9 of I comprise the massive metallic portion 11 provided With a `suitable recess 14 Within which the focal surface 8 of platinum or other resistant material is mounted at a suitable inclination. The radiation from 'the focal surface may thus pass throughva lateral aperture in the side of the `target Which may if desired be covered by afW'indow 26 formedof a thinfsheet of 'aluminum or other suitable material Which is substantially transparent to X-rays, butijmpervious to other undesirable radiation Which is thereof lead glass or other material substantially impervious to X-rays may be mounted around the body of the tube so as to .still further cut oft' undesirable radiationwithout interrupting the useful cone of rays 27 issuing through the Window 26. If desired the tubes may be provided with the usual' vacuum regulators indicated as comprising the arm 28 having the regulator terminal 29 fused therein and provided lWith suitable regulating material 30.-

Having described this invention :in connection with a number of illustrative embodiments thereof, to the details of which disclosure the invention is not of course to be limited,`what is claimed as lnew and what i's desired to be secured by Letters Patent is setA forth inthe appended claims.

1.-`The X-ray tube having a massive target of material substantially impervious to X-rays and provided With^a deep recess to receive the cathode stream entering sald target, there being a resistant lining in said recess upon which said cathode stream strikes, a cathode to coperate'with said target, said tube .havinp a substantially cylindrical glass body c osely surrounding said target andsaid cathode, intercepter'sformed on said target to minimize the discharge. of undesirable radiation through the opening -in said target through which the cathode Stream enters,f a. Window of i material substantially transparent to Xrays mounted.

Yon said ,target to V'cover a lateral opening therein through which theX-ray cone passes before striking the body -of said tube and a jacket of material substantially impervious .to X-rays closely surrounding the cylindrical portion of said 'tube body.

2n'l`he X-ray tube having a massive target of material substantially impervious to X-rays and provided with a deep recess to .receive the cathode stream entering Said target, a cathode mountedy in said tube to coperate With said target, said tube beingv formed with a substantially cylindrical glass vbody closely sulrrounding said target and cathode, intercepters formed on said target to' minimize the discharge of undesirable radiation therefrom and a Window substantially transparent to X-rays mounted .on said target over a lateral discharge opening therein through Which the X-rays pass before strikingthe body of said tube.

3. rIhe X-ray tube having a target subi stantially-impervious to Xrays and provided with' a deep recess'to receive the cathode stream entering said target, a cathode mounted in said tube to coperate `with said target, said tube having asmall glass body closely /iilclosing said target and said cathode and "a Window of material` substantially transparent to X-raysand intercepting undesirable radiation mounted Within said tube and through Which the X-rays pass before striking the body of said tube- 4. The `X-rayq tube having a target provided With a resistant lining to receive the cathode stream, a cathode mounted Within said tube to coperate With said target,.said tube having a substantially cylindrical glass body in close `lateral en agement with said target and said catho e, meansf mounted Within said tube to intercept the undesirableradiation from said target and a Window rays and intercepting undesirable lradiation mounted' Within sald tube and through of material substantially transparent to X- Which the useful X-rays pass before striking the body of said tube. Y I

5. The Xfray tube having a targetA provided 1with a resistant lining upon which.

' the cathode stream strikes, a cathode mounted Within said tube to coperate with said target, said tube havinga lglass body of small lateral dimensions to closely engage said target and said cathode, means on said target to intercept undesirable radiation therefrom and a Window mounted within said tube and substantially transparent to X-rays and impervious to undesirable radiation throughwhich the useful X-rays pass before striking the body of said tube. e if l 6. The X-ray tube having amassive taret of material substantially impervious to.

-rays and provided Wit-ha deep recess to receive the .cathode stream entering said target, a cathodemounted within'said tube to coperate vwith said target, intereepting means on said target to intercept undesirable radiation therefrom andl a window of material substantially/trans arent tofX-raysand impervious lto undesira le radiation mount- Y and a Window of material substantia ly ed within said tube in the path of the useful l transparent to X-rays and impervious to X-rays before they strike the body of said undesirable radiation mounted within said tube. tube in the ath of the useful X-rays before 10 7il 'he X-rayd tubeh havingcgf1 a target, a they strike t e body of said tube. cat 0 e mounte Wit in sai tube to cooperate Wit-hin said target, intercepting l EUGENE W' CALDWELL l Witnesses: I HARRY L. DUNCAN, l JOSEPH J. COLLINS.

means mounted Within said tube to intercept undesirable radiation from said tar et 

